Measuring a Power Plant

March 23, 2022
 by Paul McGowan

As of late, we've gotten a lot of folks wondering about how Power Plants measure and if they match their specifications.

Specifically, the P12 Power Plant.

It's always interesting to me how rumors and misinformation travel so quickly throughout the community. I suppose it's a good thing that people are so interested.

In response to so many questions, I figured our best bet would be to engage the person who actually designed the Power Plant, our chief engineer, Bob Stadtherr.

If you have a few minutes (and are interested), we've put together a video of how to properly measure a Power Plant's output impedance, what it means, and why it's important.

We also cover MultiWave and what it is and why it too is important, as well, of course, as correcting the shape of the AC waveform.

We've done our best to keep it simple and understandable.

Go here to watch the video.

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34 comments on “Measuring a Power Plant”

  1. Thanks for that Paul (and Bob). It filled in a few gaps, at least in my understanding, of how the PowerPlants are so effective at improving the sound of my system.

  2. This is very interesting and a great example of how measurements, marketing and people's understanding often collide. Case in point- the reduction of harmonic distortion in the incoming AC signal by the powerplant is measured and touted as a benefit. Later on, multi wave is another feature that is discussed, which actually increases distortion of the AC waveform. If low distortion is good, then multi wave must be bad. Numbers don't lie! But it requires a deeper understanding of the specifics of how power supplies react with the supplied power to also differentiate the 2 distortion measurements and realize that one gives benefits under specific conditions. It would be great if higher measurement numbers always meant better, but simplistic réduction of concepts into more=better/less=worse clouds the appropriateness of the testing. Worse, it seems to strengthen the conviction of those who understand some but not the whole picture. Not that anyone sees the whole picture at this point, but you get what I'm saying. Point is, correct measurements matter, but the end use for our toys is to make beautiful music, and that should be the final criteria to know if one has succeeded.

  3. As an FYI, I think the sudden interest has come due to a review video posted on YouTube by Audio Science Review of a P12 that was sent in to him to be measured. I think it's fair to say it was not a glowing review. He posted a follow up as well because he took his initial measurements of the output impedance from the wrong outlet on the P12.

  4. Speaking of which, I was planning to purchase a new PowerPlant 3, but just found that my brother has an old one, probably 2003 or so, that he's willing to sell for a song (not sure which song). He is even more of an audiophile than I am, so I'm sure it's in fantastic (power) condition. But I'm wondering if there might have been a lot of intervening development for the product in the past 15 years? I'd sure rather put the money toward something else if I'm going to get pretty much the same advantages from the old one. Any comments would be appreciated.

    1. JL,
      Ask him if you can audition it first...2 weeks should be enough.
      Use it for a week & then don't use it for 4 days & then use it
      again for the last 3 days of the two week auditioning process.
      Your ears should be able to tell you by then whether it's worth
      you having to sing 'Bohemian Rhapsody' for 😀

    2. JL, I have every generation of power regeneration that PS Audio has produced. They will all make an improvement in your system. I would, however, say that the last two generations are a cut above the earlier ones. I still have my original P300 in storage for sentimental reasons.

  5. I recently replaced my Niagara 3000 with a PSA P15. OMG there was a huge difference and I loved it. Shortly after that I purchased your Stereo Set-up guide and it took my system to another level. Anyway Paul could we see a picture inside the magic box. I would love to see the equipment layout of the power plant.

  6. The mystery of mains supply: why does the multi-meter shows 122 Volts coming from the wall wart while the P12 shows an input voltage of some 117 Volts only, Paul????

    1. ps, You are confused. First, there is no wall wart, the power is coming directly from the wall socket at the back of the lab bench. Without the P12 the wall voltage is 122V with no load and with a load 117V ( I am not showing the decimal numbers ). When the P12 is used the no load voltage out of it is 120V ( you can adjust it to be 122V if you wanted to, but that is not important ) and with load the P12 is 119V. The important thing here is the voltage drop when load is applied without the P12 is about 4V to 5 V and with the P12 the voltage drop when load is applied is less than volt ( this requires the decimal numbers to get the correct result ).

      I suggest you might want to watch the video again and take notes.

      1. Thanks, Tony. I indeed carefully watched the most informative video. But here I referred to the "voltage-in" value indicated on the inbuild screen (!) of the P12. Paul made some close-up shots and I wonder if the P12 measures differntly or if it is connected to another mains supply.

  7. ???
    Is there not a “ filter capacitor “on the input side of amps to clean up this apparent
    “Problem” that the power plant is to remediate????

    1. Take my incoming AC for example, it runs >6% THD most of time and can even get upwards of >8% THD for which the P10 I use works well in cleaning up the power delivery a filter cannot, and filters that are common mode should be used for amps, as differential is better suited for constant current, like sources. as they can limit power. And neither filter can fix the power, only subtract noise. Just sayin'

    2. Larry, There is a difference between cleaning up and starting over. Every manufacturer of audio gear will tell you that their power supply is capable of handling any noise on the power lines ( the filter capacitor ) and all makers of power conditioners will tell you the same thing. This may or may not be true, it really doesn't matter. The main purpose of the power regenerator is to supply power that remains at a constant voltage level when your audio gear requires current ( i.e. low output impedance ). It does this by generating it own sine wave power signal. The fact that it is an almost perfect sine wave is a wonderful consequence of power regeneration, but there are no "clean by filters" used.

  8. There was not a shred of evidence that this "effect" of the Powerplant transferred to any equipment connected to it. ASR already demonstrated that the PP did reduce distortion, that is granted. What is clear is that it has no effect on equipment connected to it. Modern power supplies are designed to deal with varying and dirty voltages. Paul himself claimed that power supplies are already excellent. Especially, if you're going to spend in expensive equipment. But even a $300 DAC gets no improvement from it.

    Many years ago, I had a preamp, a Classe DR-5 that had very poor signal to noise ratio for the phono input. You could measure it and it was bad. And you could hear the hiss from the speakers when the phono input was selected. Measurement directly correlated to what you could hear. Interestingly, in modern powered speakers, the level of hiss is reported as part of the system. Once I changed the phono preamp to a better one, the hiss was reduced significantly. Direct measured correlation from the device to what you obviously could hear and measure downstream. But the change occurred in the audio signal. Not in the power supply. You didn't need "golden ears" to hear lower hiss.

    As I have said, it is granted that the PP has lower distortion (unless you digress to the multi wave thing when you add it again, whatever!) but not a single piece of equipment has measured better as a result of having cleaner power within the specifications of the equipment. If the voltage from the wall is so poor, I don't think that even the PP would work. Power supply is strongly filtered out of the audio signal.

    Finally, the issue of current is another smoke screen. I don't know of many amps that produce constantly 300W with music. Maybe for brief moments, but never as a constant. This is what the amp's power supply is designed to do.

    I am sorry, but this explanation has not cleared anything.

    1. To be fair, my Class H amp pulls 350+ watts at idle when in Class A, with peaks to well over 600 with music content playing at 90dB audio peaks.

      1. Yeah that is pretty serious. You need output power to be consistent with no voltage drop, otherwise your equipment will sound anemic. You must have been floored with the before and after upon inserting a P10 in your chain. 🙂

        1. There are some who don't take into account readily that Class A operation is roughly about 30% efficiency. So that 15 watt a channel Class A stereo amp will soak up over 100 watts at idle. Scale up depending on output, and some large Class A amps pull as much as 1kW at idle with no music information playing. Of course, your room heating requirements and your relationship with you local electric company and the bill they provide will also reflect this wonder. But I do love the musical results from Class A operation.

          1. It is not just Class A operation. Until 2019 I was using two c-j Premier 12 monoblocks as the power amps in my system. They each produce 140W and are Class AB amps. When I hooked both to a PS Audio P10 as soon as I turned on the amps there was a 400W power draw. I scratched my head, no music was playing and they are Class A/B. Each amp has 4 6550 out put tubes run in the ultalinear mode. Each tube as a cathode heater that comes on as soon as the amp turns on. So a good portion of the 400W at idle is due to the cathode heaters. Think of it as eight 50W light bulbs.

            In comparison for audio in my video system I use a solid state 200W per channel stereo amp. At idle it consumes less than 40W!

            1. Yeah, I get it. If I keep my foot out of the pedal, (no Auto Class A) I get lower current at idle requirements, and it sounds really good in Class AB, but the sonic differences in Class A can't be denied.

    2. My experience with all kind of power conditioners or power filter was: they all rob dynamis/punch resulting in a less vivid/lively sound. Thus no recommendations for power amps. Only PS Audio`s power regenerators (PPP and P10) did no harm and offer additional surge protection. I never heard any improvements in sound quality. Adding some "esoterical" distortions to the voltage supply is a concept chosen also by Ansuz Audio from Denmark, a concept known from radar technology.

    3. I know you don't buy any of the changes heard from using a Power Plant and that's fine. The video was never intended to show that because it's a ludicrous idea of having a listening meter or whatever it is that might make you happy that there is a change.

      As I have written on numerous occasions, life's a bit too short to attempt changing someone's mind when it's made up.

      That said, CTA, I would very much appreciate a modicum of respect by not using words like "smokescreen" as it implies the measurement video was designed with something shady in mind—a way to pull attention from what matters. That's not true and it is mean spirited. Please refrain from comments like that. They are not helpful to the community.

      You're welcome to voice your opinion, just keep the meanness and aspersions away. The video was exactly what it says it was. A way to show how to measure a Power Plant and what those measurements mean.

      1. Paul,

        I am sorry but I don't agree with your characterization. You were insufficiently clear in the video review. You did not state which output was used. The only thing you made an attempt was to report "impedance (resistance)" of the PP output. You know very well that the ASR review indicated differences between the HC and other outputs. You did not show that. Unfortunately, you also provided confusing or equivocal explanations in your forum about this. The video did not clarify them.

        The video said PP reduces distortions in the "wave". No one disagrees with that. You then stated that the multi wave added distortions back. Which one is it? Distortions are good or bad?

        As YOU have indicated many time, the purpose of power supplies is to rectify and "clean" the voltage form the wall. They are designed to work within parameters.

        If someone has an equipment with a power supply that is so poor that will n0t do so, then they should replace that piece of equipment and not spend $5k in a PP. As I said, even $300 DACs are virtually immune to "wall power' issues.

        Your argument for PP was clever and theoretically interesting. Unfortunately, the implementation did not result in what you set to accomplish because power supplies achieve this much more efficiently (and cheaply).

        I am still trying to figure out the difference between the PS outlet I have at home and the Hubbell Hospital grade I bought at the store. One cost $49 and the other less than $7. Both are identical and built by the same company. I am frustrated I didn't figure out this before.

        Oh, and thanks for eliminating the insult by the man that called a "moron" to a blind contributor for not "seeing" a section of your site. Go figure. (Please, feel free to edit or remove this last sentence).

        1. Thanks, Carlos. I will see if I can clear the mud for you regarding the distortion issue you refer to.

          Here's a case where the distortion measurement is important only for a few reasons and it is not this distortion itself that is important. So, for example (ignoring MultiWave for now), if the incoming AC waveform is mishappen in the main body but not at the peak, then the distortion figure really doesn't matter. If the distortion measurement is indicative of a flat topped waveform (at the peak) then it matters greatly because of the loss of charging ability. But it isn't the added harmonics that matter at all. They don't. We include the THD monitor for an entirely different reason.

          Years ago, there were many competitors making wild claims about how their power conditioners fixed the incoming waveform. And they did not. We included it so people could power their PPs with the "fixed" AC and see it wasn'tr really fixed at all.

          What matters is the flattopping of the AC. Distortion, per se, doesn't matter (which is also why adding 3d harmonics to extend the charging time matters but the added distortion does not). Put another way, it is not the distortion that matters (as it might in the actual signal) but rather the cause of the distortion.

  9. Thank you for a very informative video. I have always understood that the term impedance of a source actually means behavior under load. I understand that such a simplification of the entire distribution chain to a "black box" is all we need from our point of view. Now we also know the formal definition and we have instructions for easy orientation measurement.

  10. It is a good video. Really helped me understand the P12’s functionality with big amplified products that draw quite a bit of power and that you need harmonics. It is not a bad thing even though it may not measure well to the purists.

  11. Hi there.
    I love all this tech stuff, keep up the great work.

    Can I ask with the increase in the sine waves duration at its peaks does other equipment, amps, CD player etc try to filter or condition this back out again? Surely they have some kind of filter to stop any harmful incoming power variations. It saying that the increase with the power plant is harmful but just curious.

    Also I wonder how the power plant copes with multiple loads at once? Say you had multiple amps all trying to draw as much as they could at once how does this effect the power plant and it’s ability to maintain the nice output.

    Thanks heaps

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